/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package java.text;

import java.io.InvalidObjectException;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * An {@code AttributedCharacterIterator} allows iteration through both text and
 * related attribute information.
 *
 * <p>
 * An attribute is a key/value pair, identified by the key.  No two
 * attributes on a given character can have the same key.
 *
 * <p>The values for an attribute are immutable, or must not be mutated
 * by clients or storage.  They are always passed by reference, and not
 * cloned.
 *
 * <p>A <em>run with respect to an attribute</em> is a maximum text range for
 * which:
 * <ul>
 * <li>the attribute is undefined or {@code null} for the entire range, or
 * <li>the attribute value is defined and has the same non-{@code null} value for the
 * entire range.
 * </ul>
 *
 * <p>A <em>run with respect to a set of attributes</em> is a maximum text range for
 * which this condition is met for each member attribute.
 *
 * <p>When getting a run with no explicit attributes specified (i.e.,
 * calling {@link #getRunStart()} and {@link #getRunLimit()}), any
 * contiguous text segments having the same attributes (the same set
 * of attribute/value pairs) are treated as separate runs if the
 * attributes have been given to those text segments separately.
 *
 * <p>The returned indexes are limited to the range of the iterator.
 *
 * <p>The returned attribute information is limited to runs that contain
 * the current character.
 *
 * <p>
 * Attribute keys are instances of {@link AttributedCharacterIterator.Attribute} and its
 * subclasses, such as {@link java.awt.font.TextAttribute}.
 *
 * @see AttributedCharacterIterator.Attribute
 * @see java.awt.font.TextAttribute
 * @see AttributedString
 * @see Annotation
 * @since 1.2
 */

public interface AttributedCharacterIterator extends CharacterIterator {

  /**
   * Defines attribute keys that are used to identify text attributes. These
   * keys are used in {@code AttributedCharacterIterator} and {@code AttributedString}.
   *
   * @see AttributedCharacterIterator
   * @see AttributedString
   * @since 1.2
   */

  public static class Attribute implements Serializable {

    /**
     * The name of this {@code Attribute}. The name is used primarily by {@code readResolve}
     * to look up the corresponding predefined instance when deserializing
     * an instance.
     *
     * @serial
     */
    private String name;

    // table of all instances in this class, used by readResolve
    private static final Map<String, Attribute> instanceMap = new HashMap<>(7);

    /**
     * Constructs an {@code Attribute} with the given name.
     *
     * @param name the name of {@code Attribute}
     */
    protected Attribute(String name) {
      this.name = name;
      if (this.getClass() == Attribute.class) {
        instanceMap.put(name, this);
      }
    }

    /**
     * Compares two objects for equality. This version only returns true
     * for {@code x.equals(y)} if {@code x} and {@code y} refer
     * to the same object, and guarantees this for all subclasses.
     */
    public final boolean equals(Object obj) {
      return super.equals(obj);
    }

    /**
     * Returns a hash code value for the object. This version is identical to
     * the one in {@code Object}, but is also final.
     */
    public final int hashCode() {
      return super.hashCode();
    }

    /**
     * Returns a string representation of the object. This version returns the
     * concatenation of class name, {@code "("}, a name identifying the attribute
     * and {@code ")"}.
     */
    public String toString() {
      return getClass().getName() + "(" + name + ")";
    }

    /**
     * Returns the name of the attribute.
     *
     * @return the name of {@code Attribute}
     */
    protected String getName() {
      return name;
    }

    /**
     * Resolves instances being deserialized to the predefined constants.
     *
     * @return the resolved {@code Attribute} object
     * @throws InvalidObjectException if the object to resolve is not an instance of {@code
     * Attribute}
     */
    protected Object readResolve() throws InvalidObjectException {
      if (this.getClass() != Attribute.class) {
        throw new InvalidObjectException("subclass didn't correctly implement readResolve");
      }

      Attribute instance = instanceMap.get(getName());
      if (instance != null) {
        return instance;
      } else {
        throw new InvalidObjectException("unknown attribute name");
      }
    }

    /**
     * Attribute key for the language of some text.
     * <p> Values are instances of {@link java.util.Locale Locale}.
     *
     * @see java.util.Locale
     */
    public static final Attribute LANGUAGE = new Attribute("language");

    /**
     * Attribute key for the reading of some text. In languages where the written form
     * and the pronunciation of a word are only loosely related (such as Japanese),
     * it is often necessary to store the reading (pronunciation) along with the
     * written form.
     * <p>Values are instances of {@link Annotation} holding instances of {@link String}.
     *
     * @see Annotation
     * @see java.lang.String
     */
    public static final Attribute READING = new Attribute("reading");

    /**
     * Attribute key for input method segments. Input methods often break
     * up text into segments, which usually correspond to words.
     * <p>Values are instances of {@link Annotation} holding a {@code null} reference.
     *
     * @see Annotation
     */
    public static final Attribute INPUT_METHOD_SEGMENT = new Attribute("input_method_segment");

    // make sure the serial version doesn't change between compiler versions
    private static final long serialVersionUID = -9142742483513960612L;

  }

  ;

  /**
   * Returns the index of the first character of the run
   * with respect to all attributes containing the current character.
   *
   * <p>Any contiguous text segments having the same attributes (the
   * same set of attribute/value pairs) are treated as separate runs
   * if the attributes have been given to those text segments separately.
   *
   * @return the index of the first character of the run
   */
  public int getRunStart();

  /**
   * Returns the index of the first character of the run
   * with respect to the given {@code attribute} containing the current character.
   *
   * @param attribute the desired attribute.
   * @return the index of the first character of the run
   */
  public int getRunStart(Attribute attribute);

  /**
   * Returns the index of the first character of the run
   * with respect to the given {@code attributes} containing the current character.
   *
   * @param attributes a set of the desired attributes.
   * @return the index of the first character of the run
   */
  public int getRunStart(Set<? extends Attribute> attributes);

  /**
   * Returns the index of the first character following the run
   * with respect to all attributes containing the current character.
   *
   * <p>Any contiguous text segments having the same attributes (the
   * same set of attribute/value pairs) are treated as separate runs
   * if the attributes have been given to those text segments separately.
   *
   * @return the index of the first character following the run
   */
  public int getRunLimit();

  /**
   * Returns the index of the first character following the run
   * with respect to the given {@code attribute} containing the current character.
   *
   * @param attribute the desired attribute
   * @return the index of the first character following the run
   */
  public int getRunLimit(Attribute attribute);

  /**
   * Returns the index of the first character following the run
   * with respect to the given {@code attributes} containing the current character.
   *
   * @param attributes a set of the desired attributes
   * @return the index of the first character following the run
   */
  public int getRunLimit(Set<? extends Attribute> attributes);

  /**
   * Returns a map with the attributes defined on the current
   * character.
   *
   * @return a map with the attributes defined on the current character
   */
  public Map<Attribute, Object> getAttributes();

  /**
   * Returns the value of the named {@code attribute} for the current character.
   * Returns {@code null} if the {@code attribute} is not defined.
   *
   * @param attribute the desired attribute
   * @return the value of the named {@code attribute} or {@code null}
   */
  public Object getAttribute(Attribute attribute);

  /**
   * Returns the keys of all attributes defined on the
   * iterator's text range. The set is empty if no
   * attributes are defined.
   *
   * @return the keys of all attributes
   */
  public Set<Attribute> getAllAttributeKeys();
};
